Growth Performance and Carcass Quality of Pigs Housed in Hoop Barns Fed Diets Containing Alternative Ingredients

Raising pigs in large groups in deep bedded hoop barns is receiving increased attention from producers and consumers interested in systems that are perceived to provide improved welfare for pigs. Unfortunately, these systems usually produce pigs that are fatter than similar pigs raised in conventional confinement housing systems. So, our objectives were to determine if dietary manipulation may be a useful tool for controlling increased carcass fat often observed in pigs raised in hoop barns and to assess the effect of housing and feeding system on pork quality. Specifically, we wanted to determine if a diet based on alternative grains (AG; barley, oats, buckwheat, field peas, and expeller soybean meal) would decrease carcass fatness and support growth performance of pigs housed in hoop barns (H) similar to pigs fed diets based on corn and soybean meal (CS) that were housed in an environmentally-controlled confinement barn (C). To achieve this objective, pigs (74 lb) were housed in pens in hoop barns (20 ft by 80 ft; 80 mixed sex pigs/pen) or in a confinement barn (10 ft by 15.5 ft; 15 mixed sex pigs/pen). Pigs housed in hoop barn were fed CS or isolysinic diets containing AG in a three-phase feeding program. Pigs housed in the confinement barn only received CS diets. Housing and dietary treatments were replicated over winter and summer seasons for a total of 4, 4, and 14 pens/treatment for HCS, HAG, and CCS treatments, respectively. Pigs were marketed individually when they reached 250 lb body weight. The housing and dietary treatments had similar effects on pigs regardless of the season in which the trial was conducted. Average daily gain (1.91, 1.94, 1.75 lb; MSE = .002) and feed/gain (2.97, 3.16, 3.51; MSE = .026) to the date when the first pigs were marketed for CCS, HCS, and HAG, respectively, were depressed (P < .03) by HAG compared with HCS while ADFI (5.69, 6.10, 6.13 lb; MSE = .08) was greater (P < .05) for HCS compared with CCS pigs. Last rib fat depth (.93, 1.02, .92 in; MSE = .002) was greatest (P < .05) for HCS pigs, while percentage carcass lean (54.42, 55.16, 55.48; MSE = .63) tended to be less (P < .07) in HCS vs CCS pigs. A trained sensory taste panel detected no differences in tenderness, juiciness, or overall desirability of pork loins (r = 20/treatment) collected from pigs harvested on the same day during the winter season. Inclusion of alternative grains in diets for pigs housed in hoop barns depressed growth performance and elicited minor improvements in carcass quality. Eating quality of pork was not influenced by housing system or inclusion of alternative grains in the diet.